1. Field of the Invention
This invention relates generally to mechanized photographic film processors, and more specifically to a photographic film processor incorporating an auxiliary power source.
2. Description of the Prior Art
Processing of photographic film involves a series of steps such as developing, bleaching, fixing, rinsing, and drying. These steps lend themselves to mechanization by conveying long strips of film sequentially through a series of stations or tanks, each one containing a processing liquid appropriate to the process step at that station.
In the current state of the art, an automated photographic film processing apparatus typically employs microcomputer control of its several functions. The prior art includes Japanese patent application No. 213756/1983, laid open as No. 104944/1985 on June 10, 1985; and Japanese patent application No. 223802/1983, laid open as No. 115937/1985 on June 22, 1985. These Japanese publications each disclose an automated, microcomputer-controlled, film processor system. The first of these includes a system wherein a power supply monitor responds to a drop in primary voltage to switch to a back up battery, and also to reset the controllers to prevent runaway. The second includes a system wherein the microcomputer generates a signal for every program cycle. Supervisory apparatus is provided to monitor these signals and, in response to failure thereof, generate a reset signal to a volatile RAM and to inlet and outlet data ports, and an actuating signal to the driving means. All of this is for the purpose of completing a processing cycle despite a microcomputer failure.
The above-cited prior art suffers from the disadvantage that, while provisions are made to provide back-up power to the computer/controllers, no provisions are made for physically completing the processing of film in progress during the power failure. Thus, if the main power is unavailable for any substantial period of time (i.e. more than a few seconds), the film currently being processed will remain stationary in the processing fluid and be ruined.
It would thus be desirable to provide a photographic processor wherein, in the event of a power failure, auxiliary power is supplied to complete the processing of film in progress. Such a processor should function substantially automatically, and should move any film in progress physically through the remaining processing liquids so as to complete its processing in a satisfactory manner.